1. Field of the Invention
The present invention relates generally to a mechanical broadhead for attachment to an arrow and, in particular, to a mechanical broadhead that has blades which are retracted into the body of the broadhead during flight and open upon impact with the target.
2. Description of Related Art
Previously designed mechanical broadheads that are well-known in the art were constructed to lessen the wind effects on the arrow and to provide a wounding shot that would kill the animal more quickly. There have been various designs that enable the blades to be held in during flight and to expand outward upon impact. The retractable blades in various prior art designs enable the arrow to fly straighter than a fixed blade broadhead because of the elimination of the extended blades that are able to deter the arrow off target (wind plane). Also, as the blades are extended, the intention is to cut a hole that will lead to hemorrhaging, resulting in a faster kill of the target animal. Some of the past designs have put much stress on the blades, which posed the threat that the blades would crack upon striking the target. Also, many of the past broadheads had blades that would extend from the front to the back, which slowed the arrow upon entry and decreased shot inertia, thus creating less penetration.
U.S. Pat. No. 6,517,454 to Barrie et al. describes a broadhead body as a single, longitudinally extending passage for receiving blades. The blades are held within their respective grooves with friction holding members which permit rearward sliding movement, resulting in outward expansion. During flight, the blades are not fully contained within the body.
U.S. Pat. No. 6,398,676 to Mizek describes a broadhead with blades that can be maintained in a normally closed position, with a major portion of each blade being housed within a slot of the body, and the blades pivoting rearwardly into an open position upon target impact. The blades have a rounded blunt tip portion that initially contacts a target. The arrowhead also contains various types of springs and engaging elements that can be used to maintain the blades in a normally closed position, which also provide a bias force that can be overcome by an opening force applied to the blade when in the closed position.
U.S. Pat. No. 6,270,435 to Sodaro describes spring-loaded blades that release and penetrate a target as the target is struck by the arrow. The externally exposed blades are not concealed within the body and are held together by a releasable ring.
U.S. Pat. No. 6,015,357 to Rizza discloses a broadhead for use as both an expandable blade head and a fixed blade head. The broadhead is described as a blade assembly that has an elastic ring which extends around the hypotenuse of each blade and in one annular groove in the body when the blade is in the retracted mode, with the tension of the elastic ring and the annular groove chosen determining the amount of force necessary for the blade assembly to achieve an expanded position, and with the blade assembly achieving the expanded position after the blade assembly has entered a prey. The barb on each blade contacts hard tissue causing the three blades to pivot outwardly and backwardly until the base of each blade sits in the associated slot and the elastic ring jumps out of the groove and becomes lodged around the base of each blade, causing the blade assembly to be maintained in the expanded position.
U.S. Pat. Nos. 5,112,063, 5,100,143, and 4,998,738 to Puckett and 5,082,292 to Puckett et al. describe broadheads for hunting arrows wherein the broadheads have deployable cutting blades which are held against the broadhead body during flight. U.S. Pat. No. 5,112,063 teaches the use of a tubular restraint for holding the cutting blades against the broadhead body during flight. When the broadhead impacts against an animal, a plunger, which is slidably mounted in the front of the body, is forced into the body and causes the blades to be deployed out of the slots. As the blades are moved out of the slot, the tubular restraint is cut from the body by the cutting edge. U.S. Pat. Nos. 5,100,143 and 4,998,738 teach a broadhead that includes a pair of upper blades and a pair of lower blades which are held within slots in a cylindrical body while the arrow is in flight. Upon impact with an animal, a plunger tip slides into the cylindrical body and upper and lower blades are forced to their open position by acting against the cam surfaces positioned within the cylindrical body. A C-shaped ring performs the function of holding the plunger tip in its extended position in flight and locking the blades in their open position upon impact. U.S. Pat. No. 5,082,292 to Puckett et al. teaches a broadhead with deployable cutting blades which are cammed open from slots in a cylindrical body as the plunger impacts against a game animal. The cutting blades are connected by pivot pins to the plunger. The cutting blades are pivotable when the broadhead is in an open position from the open, cutting configuration, which causes maximum hemorrhaging to a non-barbed configuration. Similarly to the '063 patent, a tubular restraint serves to hold the cutting blades within their respective slots during the flight of the arrow.
U.S. Pat. No. 5,102,147 to Szeluga discloses a ballistic broadhead assembly that maintains the blades, pivotably mounted on an actuating plunger, in a retracted condition until impact, thereupon thrusting them outwardly and forwardly for maximum effect, and ultimately constraining them against full retraction in a partially extended, optimal position. An additional pair of fixed blades may be mounted adjacent the rearward end of the body.
U.S. Pat. No. 4,932,671 to Anderson, Jr. describes an expandable blade broadhead that has a plurality of blades pivotally mounted on a circular ring. The ring is retained between a cap mounted on a stud extending from the front end of a ferrule and the ferrule. A hardened steel tip is slidably mounted in a bore in the cap, and is formed with a rearwardly facing cam surface. The blades are normally held retracted in slots in the ferrule body and cap, and the tip is normally held in an extended position. When the broadhead impacts a target, the tip is forced rearwardly, forcing the cam surface against the blades pivoting them out of the slots to a rearwardly inclined position. To facilitate extraction, the blades may pivot freely to a forwardly inclined position and the rear edges of the blades are sharpened.
U.S. Pat. No 4,099,720 to Zeren describes an expanding arrowhead having pivotally mounted blades within slots of a housing. The blades are retracted for minimum outward extension during flight but expanded and retained in an outwardly extended position upon impact with a target. The blades are retained in the retracted position by frictional engagement with the slots or by frangible or resilient members. Minimal size with maximum blade mounting strength can be obtained by orienting the blade mounting slots within the body in an offset relation to the central axis thereof. The blades are retained by transverse set screws, retaining pins or the like for easy attachment or removal. The blades can be retained in a forwardly oriented direction by a frictional engagement means, an elastic or frangible band, slotted frangible cap, or the like.
Each of the above-described previously used arrowheads operate differently and utilize different arrangements for retaining the blades in a retracted position. Some arrangements, which use frictional engagement for retaining the blades, do not appear as though they will work properly. Some arrangements are complex and require a large number of working parts. Other arrangements require specially machined components in order for the blades to deploy properly. What is needed is a simple yet effective design for holding cutting blades of a broadhead in a retracted position during flight and can quickly and effectively deploy these blades upon contact with a target, which is generally capable of use on most broadheads with deployable blades.